thermalmodel in pde toolbox: location dependent thermal properties

I am writing at present a phase-change related code and using pde thermalmodel as tool. In my program location dependent thermal properties (heat capacity, thermal conductivity..) are used. As always I am struggling with a code.

People who work with pde toolbox are familiar with the following function:

function k=kFunc(location, state)

k=a+b*state.u; %temperature-dependent thermal conductivity

end

Now I need to write a location dependent kFunc, but I found that the arrays of input location (location.x,location.y and location.z) does not match the node coordinate (which can be found in mesh setting, like "thermalmode.Mesh.Nodes"). It seems that toolbox define the size of location.

Therefore do you know:

How can I set the input location.x/y/z, so that its coordinates match the coordinates of nodes?

Thank you very much!